Use currentTime instead of currentThreadTime

When we check `isNotificationWithinTTL` to determine if we should display it, we should use `currentTimeMillis` (milliseconds since epoch) instead of `currentThreadTimeMillis` to determine the current time that will be used in the logic. The google sent_time is also in milliseconds since epoch.

During some testing, `currentThreadTimeMillis` is equivalent to almost 0 seconds due to it being the time a thread has been active.

While working on this, I looked at other places that used thread time inaccurately and changed to using `currentTimeMillis` instead.

Author: nan-li

OneSignalSDK/onesignal/src/main/java/com/onesignal/NotificationBundleProcessor.java

@@ -236,7 +236,7 @@ private static void saveNotification(OSNotificationGenerationJob notificationJob
             values.put(NotificationTable.COLUMN_NAME_MESSAGE, notificationJob.getBody().toString());
 
          // Set expire_time
-         long sentTime = jsonPayload.optLong(OSNotificationController.GOOGLE_SENT_TIME_KEY, OneSignal.getTime().getCurrentThreadTimeMillis()) / 1_000L;
+         long sentTime = jsonPayload.optLong(OSNotificationController.GOOGLE_SENT_TIME_KEY, OneSignal.getTime().getCurrentTimeMillis()) / 1_000L;
          int ttl = jsonPayload.optInt(OSNotificationController.GOOGLE_TTL_KEY, OSNotificationRestoreWorkManager.DEFAULT_TTL_IF_NOT_IN_PAYLOAD);
          long expireTime = sentTime + ttl;
          values.put(NotificationTable.COLUMN_NAME_EXPIRE_TIME, expireTime);

OneSignalSDK/onesignal/src/main/java/com/onesignal/OSNotification.java

@@ -146,7 +146,7 @@ private void initPayloadData(JSONObject currentJsonPayload) {
          return;
       }
 
-      long currentTime = OneSignal.getTime().getCurrentThreadTimeMillis();
+      long currentTime = OneSignal.getTime().getCurrentTimeMillis();
       if (currentJsonPayload.has(GOOGLE_TTL_KEY)) {
          sentTime = currentJsonPayload.optLong(GOOGLE_SENT_TIME_KEY, currentTime) / 1_000;
          ttl = currentJsonPayload.optInt(GOOGLE_TTL_KEY, OSNotificationRestoreWorkManager.DEFAULT_TTL_IF_NOT_IN_PAYLOAD);

OneSignalSDK/onesignal/src/main/java/com/onesignal/OSNotificationController.java

@@ -125,7 +125,7 @@ public boolean isNotificationWithinTTL() {
       if (!useTtl)
          return true;
 
-      long currentTimeInSeconds = OneSignal.getTime().getCurrentThreadTimeMillis() / 1_000;
+      long currentTimeInSeconds = OneSignal.getTime().getCurrentTimeMillis() / 1_000;
       long sentTime = notificationJob.getNotification().getSentTime();
       // If available TTL times comes in seconds, by default is 3 days in seconds
       int ttl = notificationJob.getNotification().getTtl();